The present invention relates to a method and an apparatus for transmitting and receiving television signals and, more particularly, to those capable of selecting the grade of received image quality according to the accounting system in chargeable broadcasting employing digital signals.
In the present television broadcasting, most television images are broadcasted by analog signals. In satellite broadcasting employing the present NTSC (National Television System Committee) system, a transmission speed of 100 Mbps is required, and only one channel can be broadcasted using a transmission band of 27 MHz. On the other hand, a high resolution television, such as a high-grade television, requires a transmission speed of 1.2 Gbps, that is, more than ten times as high as the transmission speed of the NTSC system.
Accordingly, digital television broadcasting has attracted attention in recent years. For example, when the present NTSC system is compressed to 1/25 using information compressing techniques, required transmission speed is only 4 Mbps, and broadcasts for six channels are possible per the present one channel. In a high-grade television, broadcasting is possible at a transmission speed of about 30 Mbps. In this way, the digital television broadcasting has various advantages over the analog television broadcasting, for example, effective use of electric wave resource, and transmission of high-quality image with less defect.
On the other hand, chargeable television broadcasting, such as BS, CS, or CATV, has spread in recent years. In the chargeable broadcasting, it is considered to vary the accounting level according to the content of program or the like.
An object of the present invention is to provide a method and an apparatus for transmitting and receiving television signals, which can provide a service at a resolution or a tone quality according to an accounting system, in digital television broadcasting.
Other objects and advantages of the invention will become apparent from the detailed description that follows.
The detailed description and specific embodiments described are provided only for illustration since various additions and modifications within the scope of the invention will be apparent to those of skill in the art from the detailed description.
According to a first aspect of the present invention, a television signal transmitting method for transmitting a digitally coded television signal includes the step of transmitting, as the digitally coded television signal, one of a video signal having a resolution and an audio signal having a tone quality, which resolution and tone quality correspond to a decoding coefficient that is input to a receiver by a user.
According to a second aspect of the present invention, a television signal transmitting apparatus for transmitting a digitally coded television signal comprises an encoding means for transmitting, as the digitally coded television signal, one of a video signal having a resolution and an audio signal having a tone quality, which resolution and tone quality correspond to a decoding coefficient that is input to a receiver by a user.
According to a third aspect of the present invention, a television signal receiving method for receiving a digitally coded television signal, comprises the steps of variably controlling a decoding coefficient value in response to an external input; and converting the digitally coded television signal into one of a video signal having a resolution according to the controlled decoding coefficient and an audio signal having a quality according to the controlled decoding coefficient.
According to a fourth aspect of the present invention, the above-mentioned television signal receiving method comprises the steps of storing the variation in the decoding coefficient value, as information, with the lapse of time; and posting the information, for a prescribed period of time, to a base station that sends the television signal.
According to a fifth aspect of the present invention, a television signal receiving apparatus for receiving a digitally coded television signal, comprises a decoding coefficient control means for variably controlling a decoding coefficient value in response to a user input; and a signal reproducing means for converting the digitally coded television signal into one of a video signal having a resolution according to the controlled decoding coefficient and an audio signal having a quality according to the controlled decoding coefficient.
According to a sixth aspect of the present invention, the above-mentioned television signal receiving apparatus comprises means for storing the variation in the decoding coefficient value, as information, with the lapse of time, and posting the information, for a prescribed period of time, to a base station that sends the television signal.
According to a seventh aspect of the present invention, a television signal transmitting method for transmitting a digitally coded television signal, comprises the steps of separating a video signal into N video signals (N=integer); and coding the N video signals individually and transmitting the coded video signals through different channels.
According to an eighth aspect of the present invention, in a television signal receiving method for receiving a digitally coded television signal, it is possible to select one of a case where all of coded N video signals (N=integer) are reproduced and a case where some of the N video signals are reproduced, in accordance with an external input.
According to a ninth aspect of the present invention, a television signal transmitting apparatus for transmitting a digitally coded television signal, comprises a video signal separating means for separating a video signal into N video signals (N=integer); and a video signal encoding means for coding the N video signals individually and transmitting the coded video signals through different channels.
According to a tenth aspect of the present invention, a television signal receiving apparatus for receiving a digitally coded television signal, comprises a video signal decoding means capable of selecting one of a case where all of coded N video signals (N=integer) are reproduced and a case where some of the N video signals are reproduced, in accordance with an external input.
According to an eleventh aspect of the present invention, a television signal transmitting method for transmitting a digitally coded television signal, comprises the steps of separating a video signal having a resolution twice as high as an ordinary resolution into two video signals each having the ordinary resolution; and coding the two video signals individually, and transmitting the coded video signals through different channels.
According to a twelfth aspect of the present invention, in a television signal receiving method for receiving a digitally coded television signal, it is possible to select one of a case where both of two coded video signals, each having an ordinary resolution, are reproduced and a case where one of the coded video signals is reproduced, in accordance with an external input.
According to a thirteenth aspect of the present invention, a television signal transmitting apparatus for transmitting a digitally coded television signal, comprises a video signal separating means for separating a video signal having a resolution twice as high as an ordinary resolution into two video signals each having the ordinary resolution; and a video signal encoding means for coding the two video signals individually, and transmitting the coded video signals through different channels.
According to a fourteenth aspect of the present invention, a television signal receiving apparatus for receiving a digitally coded television signal, comprises a video signal decoding means capable of selecting one of a case where both of two coded video signals, each having an ordinary resolution, are reproduced and a case where one of the coded video signals is reproduced, in accordance with an external input.
According to a fifteenth aspect of the present invention, a television signal transmitting method for transmitting a digitally coded television signal, comprises the steps of separating a video signal having a resolution twice as high as an ordinary resolution into a first video signal comprising high-frequency components and a second video signal comprising components other than the high-frequency components; and coding the first video signal and the second video signal individually, and transmitting the coded first and second video signals through different channels.
According to a sixteenth aspect of the present invention, in a television signal receiving method for receiving a digitally coded television signal, it is possible to select one of a case where both of a first video signal comprising high-frequency components and a second video signal comprising components other than the high-frequency components, which video signals are obtained by separating a video signal having a resolution twice as high as an ordinary resolution, and a case where one of the first and second video signals is reproduced, in accordance with an external input.
According to a seventeenth aspect of the present invention, a television signal transmitting apparatus for transmitting a digitally coded television signal, comprises a video signal separating means for separating a video signal having a resolution twice as high as an ordinary resolution into a first video signal comprising high-frequency components and a second video signal comprising components other than the high-frequency components; and a video signal encoding means for encoding the first video signal and the second video signal individually, and transmitting the coded first and second video signals through different channels.
According to an eighteenth aspect of the present invention, a television signal receiving apparatus for receiving a digitally coded television signal, comprises a video signal decoding means capable of selecting one of a case where both of a first video signal comprising high-frequency components and a second video signal comprising components other than the high-frequency components, which video signals are obtained by separating a video signal having a resolution twice as high as an ordinary resolution, and a case where one of the first and second video signals is reproduced, in accordance with an external input.